This invention relates generally to improvements in traveling irrigation systems particularly of the so-called center pivot or linear travel types used widely for irrigation of large terrain areas, such as required in the irrigation of agricultural crops and the like. More specifically, this invention relates to an improved irrigation boom assembly for mounting onto the main water distribution pipe of a traveling irrigation system, wherein the improved boom assembly comprises a relatively small number of lightweight and easily assembled components which are adaptable to accommodate a wide range of operating requirements.
Travelings irrigation systems have been widely used for supplying irrigation water to large terrain areas, particularly such as irrigation of agricultural crops and the like. In such systems, a plurality of irrigation sprinklers are mounted along the length of an elongated water distribution pipe which is in turn supported by one or more wheeled frames for traveling movement through an agricultural field. In one common form, the distribution pipe is driven through a circular pattern about a so-called center pivot whereby the sprinklers collectively provide irrigation water to a terrain area of circular shape. In another form, the distribution pipe is driven as a linear unit in a direction generally perpendicular to its longitudinal axis to traverse and irrigate a terrain area of generally rectangular shape. In both types of systems, the sprinklers are positioned to irrigate the soil in overlapping patterns and with a water delivery rate chosen to accommodate distribution pipe movement across a field at an acceptable, not unduly slow rate of travel.
While traveling irrigation systems of the type described have advantageously permitted irrigation of large terrain areas, a variety of practical limitations and difficulties have arisen. For example, the quantity of irrigation water which can be delivered to a given portion of the terrain area is limited by the rate of travel of the distribution pipe through the agricultural field. Accordingly, to achieve adequate watering, excessive water flow rates from the sprinklers are sometimes required to result in undesirble water run-off and waste. In some systems, this problem is offset by using sprinklers having an increased range of throw thereby increasing the time period during which irrigation water is delivered to a given portion of the terrain area. This approach thus permits each sprinkler to deliver irrigation water at a somewhat reduced flow rate, but, unfortunately, also requires higher energy water droplets typically of significantly larger size which are known to undesirably compact some types of soil within a relatively short period of time.
In an effort to overcome these and other difficulties, auxiliary boom assemblies have been proposed for mounting onto the water distribution pipe of a traveling irrigation system to spread the instantaneous delivery of irrigation water over a larger coverage area without requiring use of sprinklers having a long range of throw. More particularly, in such proposals, a plurality of boom assemblies are suspended from the distribution pipe to extend in a cantilevered fashion angularly forwardly and rearwardly therefrom in a generally parallel array with each boom assembly including a plurality of relatively small irrigation sprinkler spray heads for irrigating small overlapping terrain patterns. Collectively, the plurality of spray heads on the plurality of boom assemblies substantially increase the overall coverage area for any given point in time to permit relatively low flow and relatively low energy water delivery from each spray head. However, these auxiliary boom assemblies have been relatively complex in construction to include the plurality of spray heads and the required support means for structurally supporting the boom assembly, particularly when its weight is increased by irrigation water flowing to the spray heads. Accordingly, these boom assemblies have generally been constructed from a large number of parts which have required substantial time and labor to assemble and further have not been adapted for compact shipment and/or storage.
There exists, therefore, a significant need for an improved boom assembly for use with a traveling irrigation system, wherein the improved boom assembly provides the requisite structural support means in a lightweight design adapted for quick and easy assembly and further for compact shipment and/or storage. The present invention fulfills these needs and provides further related advantages.